Liquid sample processing is an everyday activity of a typical clinical, diagnostic, or research laboratory. Although the sample may include a toxic chemical or a biohazard, many conventional sample processing steps are conducted manually. Such manual processing of hazardous liquids can expose the laboratory worker to aerosols or puncture wounds. For example, sample tubes are often under either positive or negative internal pressure due to the method employed to collect the sample, changing temperature, or agitation. Opening such a tube can release an aerosol of the biohazard. Laboratories typically require employees to move samples into a large and expensive isolation hoods for opening and other steps that might release a hazardous aerosol.
Manual sample handling can compromise sample integrity. Handling dozens or hundreds of individual samples inevitably leads to human error. Human error can compromise the sample chain of custody and require costly or redundant testing and quality-control. Further, human handling of open sample tubes can lead to cross-contamination of samples.
In addition, manual sample handling can be labor intensive. Each worker can open and remove liquid from only one tube at a time. An increase in sample processing throughput is usually achieved by putting several technicians on the task in parallel. It is estimated that such manual sample processing can account for 65% of all laboratory hands-on labor costs.
In high throughput sample processing, such as whole blood or plasma analyses for infectious agents or genetic testing, large numbers of liquid samples come into the laboratories in capped and bar-coded glass or plastic vessels, e.g., VACUTAINER® tubes. Manual procedures for processing such samples can include checking the sample for clotting, scanning the barcode, verifying correspondence of sample with proper subject, placing a new number or barcode on the tube, removing the tube from a carrier, inverting the tube, uncapping the tube, disposing of the tube cap, placing the same new number or barcode on a different tube, pouring the sample into the different tube, placing the tube into a machine rack, orienting the tube for barcode reading, removing the tube from the machine rack, recapping the tube, and placing the tube into a carrier. Error in any of a variety of these labor-intensive procedures can expose a worker to hazardous substances or compromise the sample.
There remains a need for improved fluid handling systems that can rapidly and safely remove potentially harmful fluids from containers.